Electrical loud-speaking receiver



April 15, 1924.

H. KOESTER ELECTRICAL LOUD SPEAKING RECEIVER Filed June 19. 1922 gwuewtoz k brmalzffoesier.

. fitter/nu 5 Haven and State of Patented Apr. 15, 1924.

HERMAN xonsrna, or warnannmzi connncrrciirjassxenoa'ro 'rrm BRISTOL com-z ram, or warsnauar, coztnncrxcn'r; A concurrence CONNECTICUT.

' ELECTRICAL LO UQBPE AKIIiG nacnrvnn.

Application gled ma 19,1522. serial no. 5129332.

To all whom it may concern:

Be it known that I, a citizen of the United States,-and a resident of Waterbury,

Connecitcut, haveinvented certain new and useful Improvements in Electrical Loud-Speaking Re ceivels, of which the following is a specitication.

1- The invention relates-to electrical receiver apparatus for amplifyingsounds, such re-' oeiver device being generally termed loud speaking receivers? .The invention relates more particularly to that type of loud.- l5 speaker receivers in-whichthe one end ofv the actuating lever is not fixedly secured to the diaphragm of the receiver but is tensioned thereby; and in which the actuating lever is substantially of one piece and fulcrumed on one of the poles of the permanent magnet of the receiver and under the attraction of the other. M

It has for its object, in areceiver of this character, to $0 associate the diaphragm end of the lever with the. diaphragm that the former will be held centrally with respect to the latter. The invention has for its object, also, a specific form of loose connection between the said end of the lever and the diaphragm in c'ase'a. diaphragm of mica or like material is employed.

The nature of the invention, however, will best be understood when described in connectionwith the accompanying drawings, in which Fig. 1 is a longitudinal section thru the receiver device.

F ig. 2 is a horizontal section taken on the-line 2--2, Fig. 1, looking in the direction of the arrows.

Fig. 3 is a transverse section taken on the line 3-3, Fig. 1, looking in the direction of the arrows.

Fig. 4 is an enlarged detail section of the 45, positioning means forthe lever; and, Fig. 5 is a sectional detail view of a modification therein. Similar characters of reference designate corresponding parts thruout the several views.

Referring to the drawings, designates a suitable casing or container wherein the entire apparatn s may conveniently be moi. ed and housed. The device itself compr apermanent U-shaped magnet 11, one 2 in the county of New- :beingshorter than on other and having pale pieces 12 and 13 directedhtright a es from the ends thereof. The pole piece 13, furthermore, isprovidcd with a. solenoid 14 thru which current passes as received from a transmitting apparatus (not shown), and.

as is well understood. Suitable leads 15 are a connected to the said solenoid for this pur- SB'. o The -magnet' 11, in addition, carries .a sound-box 16 which is adjustably secured thereto for slight angular motion to tension a lever hereinafter set forth, the adjustment being effected for. example, thru suitablo nuts 17 working on the screw'18. A nut'19 "serves to secure the sound box and attached magnet to the casing 10;.and anoutlet 20' extends therefrom thru the said cover and may receive a suitable horn 21 01- other amplifying membeh In order toeffect the amplification, the diaphragm 22"of the sound box is to vibrated in. accordance with the pulsations received. from the transmitting circuit 15,

the diaphragm being held securely in 'the sound box 16, by nibber washers 23 or the like, in-the usual manner.- These pulsa-' tions affect the magnetic attraction of the pole piece 13 for the armature end of a free, one-piece lever 24 whose other .end is associated with the diapragm 22 which is caused tolrear thereon under a. pedetermined tension in accordance with the normal attraction of the pole piece 13 for its corresponding end. The lever 24, moreover, is fulcrumed on the other pole piece 12, merely resting thereon; but is guided against lateral displacement by; means of ears 25 downwardly directed from the sides of the lever and embracing the said pole,piece.

In the case of a lever of thisatype, if its diaphragm end has been rigidly attached to the diaphragm, the latter thru this tive connection is more or less distorted in the operation of the lever, especially should its position on the fulcrum pole piece become somewhat displaced. In accordance posiwith the present invention, a. connection bemission of the vibrations of the lever to the said diaphragm. Furthermore, in the case, of a loose connection between lever and diaunless the letter be arranged toil? be positively guided by the diaphragm and to axially more amesalthough permitting otherwise. of perfect freedom of'moyeme'nt .the influence of said magnet, the other end fitting thru the rfora tion of .the dia-' 'phragm, uiiselll i f?" thereto -;and bearing against one side onlyof the latter. I 2. -In anelectrical loud speaking receiver:

a; permanentmagnet, a centrally perforated -diaphragm,-,and mlevenhaving'one'end under the influence of said magnet, the other of the 'one with [respect to the other;

For example,- as .indicatedjn-the draw..

endzfitting' thru theiperforation of the dia- .lfismg's, the diaphragm may be centrally perphragm, unsecu red thereto and bearing forated'and a grommet or eyelet 30 inserted, 4 especially in the case of diaphrag'ms of such material as mica having laminationswhich would tend to-split' along the edge'of the j'perforationoand thus destroy the-effect of the-diaphragm. It-is desirable,'-in the case" "lof the diaphragms of this type, to include between the faces of the diaphragm and the heads .of the grommet or eyelet washers 31- of suitable material such as paper, the same being held or pinched to the diaphragm by the heads of the grommet. The diaphragm end of the lever is preferablyreduced in n this case and fitsloosely. into the grommet,', as shown; and a curved shoulderj'32 fisprln-' 't e. grommet anddesigned to conform'isubstann i other! endfbeing reduced and fitting into said grommet-andhavinga curved shoulder 'to-fit the corresponding grommet head to provide a movable joint therewith.

vided thereon below the lower he tially to thefcurvat-ure'of same; M'oreover, 1 it forms therewith substantially a ball and socket joint, sol-that the angulanmovement of the leverand"any'slight variation adjustment of the leverrelative' to its fill-Q .crum may be iicco mmo'dated without causing distortion of the diaphragm, and; whereby the resulting reproduction of the' s;o'und of the highest-quality; r 4

In Fig. .5, a means of .cehtering theflever,

with reference to the diaphragm has been indicated,;' the same beingn rmor'e especially" suitable for metaland like diaphragms in' which an indentation or recess-33 may-be provided for theend 34 of the-lever, and

desired freedom ofnioyem ent- Iclaim: 1. Inan electrical loud speaklng receiver:

a permanent magnet, a perforated-dim phragm, and a lever having one end under said grommet. Y

4. In an electrlcal loud speaking recelverz which ispreferably rounded toaiford the against one side only ofthe latter.

I 3; In an electrical loud, speaking receiver:

a permanent magnet, a perforated mica diaphragm, a grommet fittingfthe perforation "of the diaphragm and washers mounted about the grommet .and'held thereby betweenthe o posite faees of the diaphragm and the heads ofthegro havingone end under the influence of said magnet, its other end fitting into said grommet and bearing againstone head only of a permanent. magnet, -aperforated -dia- 5-. In an electricalloudspeaking receiveri mmet, and a lever .phragm,-a grommet fitting the erforation.

a-permanent' magnet, a centrally perforated.

mlca diaphragm, a ro pmet fittingthe per- -.;foration of-the diap rag'm-and paper washersamounted about the grommet and held thereby between tlieopposite'faces of the diaphragmand the corresponding heads ofv the grommet," and a lever having one end under the influence of said magnet, the other end being reducedand fitting into the grommet and having a curved shoulder to fit the corres onding rommet head to provide a movab e'joint't erewith.

Signed" at Waterbury, 1n the county 10f -New- Haven and State of Colinbcticptt-tliis 14th day of J une,.A; D. 1922. 4 IIERMAN KQESTER. 

